Trying to salvage a deck.

Our deck was stained then painted. I don’t know what type of paint. I sanded and then power washed. Now I’m trying to salvage it. What type of primer and white deck paint do I use? Does the white paint need a protective coat over it if there is such a thing?

PS- I don’t know if all the stain came off with the sanding of the railings – only the floor was power washed. I know it is a mess.